Initializes an interstitial with an ad unit created on the AdMob website. Create a new ad unit
for every unique placement of an ad in your application. Set this to the ID assigned for this
placement. Ad units are important for targeting and statistics.

Declaration

Returns the ad network class name that fetched the current ad. Returns nil while the latest ad
request is in progress or if the latest ad request failed. For both standard and mediated Google
AdMob ads, this property returns @GADMAdapterGoogleAdMobAds. For ads fetched via mediation
custom events, this property returns @GADMAdapterCustomEvents.

Declaration

Presents the interstitial ad which takes over the entire screen until the user dismisses it.
This has no effect unless isReady returns YES and/or the delegate’s interstitialDidReceiveAd:
has been received.

Set rootViewController to the current view controller at the time this method is called. If your
application does not use view controllers pass in nil and your views will be removed from the
window to show the interstitial and restored when done. After the interstitial has been removed,
the delegate’s interstitialDidDismissScreen: will be called.